Inspection points difference in Inprocess inspection in QM

Hi,

Can anybody explain the difference of the functionality of the following inspection points in Inprocess inspection in QM

100 Free insp. point

110 Inspection point dependent on event

150 Generated insp. point; quantity or time

200 Inspection based on samples

In which scenrios which one to use.

I have requirement like Production Order created for 100 qty and this order have three operations out of which second one is having in process inspection. Operation time is 4 hrs.

Req 1.

user should have the provision of doing RR for 25 qty produced means four inspection points to be generated for the inspection lot.

Req 2.

user should have the provision of doing RR for every two hrs means two inspection points to be generated.

Req3.

user should have the provision of any number of time RR. means if he do RR once then system should generate next inspection point and it should continue like this.

Please clarify in which scenario which inspection points to use .

Thanks

Vinamrath